/// <summary>
/// Evaluates quiz and survey; stores results; returns ID so client can navigate to results page.
/// </summary>
/// <param name="quiz">The user's quiz choices, JSON serialized in quiz.js.</param>
/// <param name="survey">The user's survey input (whatever was provided), JSON serialized in quiz.js.</param>
/// <returns></returns>
public IActionResult EvalQuiz([FromForm] string quiz, [FromForm] string survey,
[FromForm] string quizCount, [FromForm] string surveyCount)
{
// Parse data from query
var oQuiz = JsonConvert.DeserializeObject <IList <string[]> >(quiz);
var oSurvey = JsonConvert.DeserializeObject <SurveyData>(survey);
// Have sampler evaluate result
int score;
char[] resCoded;
sampler.Eval(oQuiz, out score, out resCoded);
// Get country from remote IP. Trickier b/c of NGINX reverse proxy.
string country;
string xfwd = HttpContext.Request.Headers["X-Real-IP"];
if (xfwd != null)
{
country = countryResolver.GetContryCode(IPAddress.Parse(xfwd));
}
else
{
country = countryResolver.GetContryCode(HttpContext.Connection.RemoteIpAddress);
}
// Store result
int nQuizCount = int.Parse(quizCount);
int nSurveyCount = int.Parse(surveyCount);
StoredResult sr = new StoredResult(country, DateTime.Now, nQuizCount, nSurveyCount, score, new string(resCoded), oSurvey);
string uid = resultRepo.StoreResult(sr);
// Response is result code, pure and simple.
return(new ObjectResult(uid));
}
/// <summary>
/// Diagnostic function: stores same item N times in a single transaction. Used to grow DB in stress test.
/// </summary>
/// <returns>UID of last stored item.</returns>
public string StoreBatch(StoredResult sr, int count)
{
long uid = 0;
lock (conn)
{
SqliteTransaction trans = null;
try
{
trans = conn.BeginTransaction();
for (int i = 0; i != count; ++i)
{
uid = getNextUid(sr.Date, trans);
storeResult(uid, trans, sr);
}
trans.Commit(); trans.Dispose(); trans = null;
}
catch (Exception ex)
{
logger.LogError(new EventId(), ex, "Failed to store quiz results.");
if (trans != null)
{
trans.Rollback();
}
throw;
}
finally { if (trans != null)
{
trans.Dispose();
}
}
}
return(uidToString(uid));
}
/// <summary>
/// Performs actual dump.
/// </summary>
private void doDumpToFile(string tsvFileName)
{
SqliteConnection dumpConn = null;
SqliteCommand cmdSelAll = null;
try
{
// For the dump, we use a separate connection
// This allows main connection to be safely accessed from other threads while dump is in progress
bool dbExists;
getOpenConn(out dumpConn, out dbExists);
using (SqliteCommand cmdPragma = dumpConn.CreateCommand())
{
// This pragma is a MUST to avoid locking the DB for the duration of the dump
// Without it, concurrent store requests will time out.
cmdPragma.CommandText = "PRAGMA read_uncommitted = 1;";
cmdPragma.ExecuteNonQuery();
}
// Dumping is rare. No need to prepare and reuse this command.
cmdSelAll = dumpConn.CreateCommand();
cmdSelAll.CommandText = sqlSelAll;
cmdSelAll.Prepare();
// Write from reader, straight to output file.
using (FileStream fs = new FileStream(tsvFileName, FileMode.Create, FileAccess.ReadWrite))
using (StreamWriter sw = new StreamWriter(fs))
using (var rdr = cmdSelAll.ExecuteReader())
{
sw.WriteLine(StoredResult.GetTSVHeader());
while (rdr.Read())
{
// uid, country, quiz_ix, survey_ix, score, res_enc, survey_enc
int dateNum = (int)(rdr.GetInt64(0) / 1000000);
int xDay = dateNum % 100; dateNum /= 100;
int xMonth = dateNum % 100; dateNum /= 100;
int xYear = dateNum;
DateTime date = new DateTime(xYear, xMonth, xDay);
StoredResult sr = new StoredResult(rdr.GetString(1), date, rdr.GetInt32(2), rdr.GetInt32(3),
rdr.GetInt32(4), rdr.GetString(5), rdr.GetString(6));
sw.WriteLine(sr.GetTSV());
}
}
dumpConn.Close();
}
finally
{
if (cmdSelAll != null)
{
cmdSelAll.Dispose();
}
if (dumpConn != null)
{
dumpConn.Dispose();
}
}
}
/// <summary>
/// Executes "store" SQL command within transaction.
/// </summary>
private void storeResult(long uid, SqliteTransaction trans, StoredResult sr)
{
cmdInsertResult.Transaction = trans;
cmdInsertResult.Parameters["@uid"].Value = uid;
cmdInsertResult.Parameters["@country"].Value = sr.CountryCode;
cmdInsertResult.Parameters["@quiz_ix"].Value = sr.PrevQuizCount;
cmdInsertResult.Parameters["@survey_ix"].Value = sr.PrevSurveyCount;
cmdInsertResult.Parameters["@score"].Value = sr.Score;
cmdInsertResult.Parameters["@res_enc"].Value = sr.EncodedResult;
cmdInsertResult.Parameters["@survey_enc"].Value = sr.GetEncodedSurvey();
cmdInsertResult.ExecuteNonQuery();
}
/// <summary>
/// Stores a new quiz+survey result in the DB.
/// </summary>
/// <param name="sr">The data to store.</param>
/// <returns>The stored item's ID, encoded as a 10-character alphanumeric string.</returns>
public string StoreResult(StoredResult sr)
{
return(StoreBatch(sr, 1));
}